Siemens SIMATIC S5-115F - Response Time in the Case of Direct Access in the Time Interrupt ob (ob 13); Response Time in the Case of Direct Access in the Process Interrupt ob (ob 2)

Rules Governing the Use of the S5-115F S5-115F Manual
10.3.3 Response Time in the Case of Direct Access in the Time Interrupt OB
(OB 13)
If the inputs are read in and the outputs are activated by direct access in the time interrupt OB, the
following applies for the response time:
T
R
T
OB 13
+T
synchr.
+T
proc.
Figure 10-3. Response Time in the Case of Direct Access in Time Interrupt OB 13
LPW
Output response
T
proc.
Read-in with LPW Input signal
OB 13
Time interrupt, e.g. every
250 msec.
e.g.
every
100
msec.
OS
bef.
user
prog.
OS
after
user
prog.
.
OB 13 OB 13 OB 13
TPW
Synchr.
time
inter-
rupt
Explanation of Figure 10-3
If input signal changes after the relevant direct access in OB 13, the change will be
recognized in the next possible OB 13 call. It is possible in the following cases:
• When the interval time for OB 13 has elapsed (250 msec. in the example)
• When the next synchronization point has been reached (100 msec. in the example or
20 msec. in general).
10.3.4 Response Time in the Case of Direct Access in the Process Interrupt OB
(OB 2)
If the inputs are connected to a module with interrupt capability and the outputs are directly
accessed in the process interrupt OB, the following applies for the response time to a falling edge
at the input:
TR T
synchr.
+T
proc.
+ T
OS
10-4 EWA 4NEB 811 6148-02